package com.feioou.blogdemo.controller;

import com.feioou.blogdemo.exception.storage.StorageFileNotFoundException;
import com.feioou.blogdemo.service.StorageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import java.util.stream.Collectors;

/**
 * @description: 文件控制器
 * @author: chenyingjie
 * @create: 2019-11-26 16:07
 **/
@Controller
@RequestMapping(path = "/file")
public class FileController {

    @Autowired
    private StorageService storageService;


    @GetMapping(path = "/uploadForm")
    public String uploadForm(Model model) {
        model.addAttribute("files", storageService.loadAll()
                .map(path -> MvcUriComponentsBuilder.fromMethodName(FileController.class, "serveFile", path.getFileName().toString()).build().toString())
                .collect(Collectors.toList()));
        return "uploadForm";
    }

    @GetMapping(path = "/{filename:.+}")
    @ResponseBody
    public ResponseEntity<Resource> serveFile(@PathVariable String filename) {
        Resource resource = storageService.loadAsResource(filename);
        return ResponseEntity.ok()
                .header(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=\"" + resource.getFilename() + "\"")
                .body(resource);
    }

    @PostMapping("/uploadForm")
    public String handleFileUpload(@RequestParam("file") MultipartFile file, RedirectAttributes redirectAttributes) {
        storageService.store(file);
        redirectAttributes.addFlashAttribute("message", "You successfully uploaded " + file.getOriginalFilename() + "!");
        return "redirect:/file/uploadForm";
    }

    @ExceptionHandler(StorageFileNotFoundException.class)
    public ResponseEntity<?> handleStorageFileNotFound(StorageFileNotFoundException e) {
        return ResponseEntity.notFound().build();
    }
}
